/**
 * @license
 * Copyright 2018 Google Inc.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import type { LayerManager, MouseSelectionState } from "#src/layer/index.js";

export function getSelectedAnnotation(
  mouseState: MouseSelectionState,
  layerManager: LayerManager,
) {
  if (!mouseState.active) {
    return undefined;
  }
  if (mouseState.pickedAnnotationId === undefined) {
    return undefined;
  }
  const renderLayer = mouseState.pickedRenderLayer;
  if (renderLayer === null) {
    return undefined;
  }
  const annotationLayer = mouseState.pickedAnnotationLayer;
  if (annotationLayer === undefined) {
    return undefined;
  }
  const managedLayer =
    layerManager.renderLayerToManagedLayerMap.get(renderLayer);
  if (managedLayer === undefined) {
    return undefined;
  }

  return {
    layer: managedLayer,
    annotationLayer,
    id: mouseState.pickedAnnotationId,
    partIndex: mouseState.pickedOffset,
  };
}
